An in-trail procedure (ITP) is a protocol followed by an aircraft that desires to change its current flight level to a new flight level by descending or climbing in front of or behind one or more potentially blocking aircraft flying at an intervening flight level. In accordance with ITP criteria, certain conditions must be satisfied before the flight crew member issues a request for clearance to proceed with the flight level change. Whether or not the conditions are satisfied will depend on a number of dynamically changing factors associated with the host aircraft and other aircraft, such as the current geographic position of the aircraft, the current speed of the aircraft, the current heading of the aircraft, the desired new flight level, and the current flight level.
Modern flight deck instrumentation might include a traffic display that provides a two-dimensional representation of a host aircraft and neighboring aircraft. Such display systems typically provide a number of parameters and visual indicators that enable a pilot to form a quick mental picture of the vertical situation of the host aircraft. For example, such a system might include displays of an aircraft symbol, the aircraft altitude, the vertical flight plan, and terrain. In this manner, a member of the aircraft flight crew can obtain information related to the vertical situation of the aircraft relative to other aircraft with a simple glance at the display system.
In some cases, the pilot of a host aircraft (also referred to herein as the ownship) may desire to perform an ITP transition to a flight level that has already been allocated to another aircraft requesting an ITP transition. Unaware of this allocation, the ownship pilot will prepare and forward an ITP request to Air Traffic Control (ATC), where the request will be evaluated and rejected because the requested flight level has already been allocated. However, the ownship pilot will not be informed of which aircraft is performing an ITP transition or the assigned ITP transition altitudes. Thus, requesting ITP approval for a transition to an altitude that has already been allocated to another ITP transition wastes both pilot time and ATC time.
Considering the foregoing it would be desirable to provide a system and method for providing a graphical/textual indication on a host aircraft's ITP display that a flight level has been allocated pursuant to another aircraft's ITP request